[quote=Lowcountry Joe;8895887]If all you change is the exhaust system, you don't need to do anything. However, if you change the exhaust system AND add a high-flow air cleaner, then you have introduced more airflow through the motor and you will need to enrich the AFR a bit.

By the way, the O2s on the HDs are 12mm "narrow band" sensors. They are able to make slight changes over a very restricted range, but not quite enough to keep your AFR where it should be if you switch out the input and output hardware.quote]

Thanks, the O2 sensors being "narrow band" type makes a lot of sense. Also, I knew I would not need fuel tuning from just a muffler change but I changed out the head pipes, too. I was hoping a small change in air flow from head pipes and mufflers would be within the range of the O2 sensors to compensate. That is why the question to begine with.

Thanks again.
David

 

If so, then the question is... How much air can they compensate for? Mufflers? Mufflers and non-catalitic head pipes? Mufflers, non-catalitic head pipes and breather?

 

Good info. I got both codes on my first ride after the headpipe and muffler change. Looking at the XiEd now.

 

Ive went so far as to borrow a motorheads small snake light camera and ran in the spark plug holes to view the appearance of my pistons, I was pleased to see a healthy layer of carbon for a bike with 10k on the clock. This does not indicate a lean condition, does it?
My spark plugs look healthy, no decel popping, bike runs just as cool as a few liquid cooled bikes ive rode, emits a healthy fuel aroma, it runs amazing, is even leaving a healthy amount of soot in the pipes.
Now someone please tell me what my lean condition is. Open pipes and ac have been on this bike for 10k miles and theres 11k on it now, with no tuner or download.
Now, if I had told you these conditions and said that I was running X brand tuner everyone would say "that is great, X makes a great tuner", but, since I said I'm not running a tuner everyone will say "oh my god, youre burning you're motor up". Kind of the placebo effect isn't it.
And if these sensors cant make up for these changes you're system will throw a code and that little yellow engine in the dash will come on. Much like an old sensor that is clogged up or one that is unplugged.
Is my bike running optimum hp and torque? probably not, but it runs like a striped *** ape on speed. Am I in danger of burning my motor up? Also a no.
I know not everyones results will be the same, nor should anyone expect them to be. Altitudes and a million other factors come in to play. But I know im definitely tired of people swearing that their bikes need a new thousand dollar tune and a dyno guy to run the **** out of their motor for 6 hours because they changed a blinker bulb. And the next guy will believe it because he needs advice and he dosent know enough to troubleshoot or find out for himself.
Internet advice is dangerous because long gone are the days of figuring **** out and paying attention to what you're doing. Maybe its because of the internet age that nobody tries to figure stuff out. Oh well, if its on the internet from a stranger it must be true.

 

Interesting and very good information. Thanks

 

RLE is essentially correct, as are the folks at Fuel Moto. The rest of what I'm reading here is unadulterated, 100% pure, undiluted Bull S*** also known as Pseudoscience, spewed forth by those that shouldn't be allowed anywhere near an actual engine let alone a keyboard.

Oxygen Sensing:
1.) The purpose of using Narrow or Wide band O2 Sensors (in what is called Closed Loop) is to keep the fuel mixture at an average of 14.7/1 (14.5 - 14.9/1 actually) from just Off Idle (~5% Throttle) to Large Throttle Openings (~50% Throttle). 14.7/1 is called the Stoichiometric Air Fuel Ratio. A Stoichiometric Air Fuel Ratio and is neither Lean nor Rich; it is exactly dead center between Lean and Rich. Up to a point, better Fuel economy will occur at mixtures Leaner than 14.7/1, and more power can be had with Air Fuel Ratios Richer than 14.7/1. With 3-Way Catalytic Converters the "Ideal" Stoichiometric Air Fuel Ratio also just happens to also deliver the best emissions control. which all things considered is a very nice coincidence . . . but it is NOT a lean mixture.
2.) If the change to the Fuel Injector pulse width, needed to obtain what looks like 14.7/1, between 5% and 50% Throttle, is beyond a programed value limit; also called the Range of Authority (ROA), the computer will set an O2 Sensor Trouble Code. So if you're not setting O2 Sensor Trouble Codes, the fuel mixture between 5% and 50% Throttle is 14.7/1.
3.) Open Loop fuel mixtures used during maximum engine power conditions (over 50% Throttle on most Motorcycles and over 80% on most Automobiles) are calibrated to deliver mixtures richer than 14.7/1 (usually around 12.0/1 to 13.0/1). Note: The base pulse widths that are programmed to deliver these rich mixtures are adjusted up or down proportionally depending on the adjustment needed to deliver 14.7/1 in Closed Loop.

Summary:
1.) Changes that are made to an engine such as Air Cleaners, Exhaust, etc. that affect the fuel mixture in Closed Loop (5% - 50% Throttle) will cause the computer to adjust the fuel delivery schedule to maintain 14.7/1. The computer will also proportionally change the injector pulse width in Open Loop. 0%-5% and 50%-100% Throttle based on the changes needed to maintain 14.7/1 in Closed Loop. Thus an engine change that requires a change in fuel delivery of "X" between 5% and 50% Throttle to maintain 14.7/1 in Closed Loop will also result in an "X" change in fuel delivery in Open Loop 0%-5% and 50%-100% Throttle. This ensures that the variables from one production engine to another, and those that occur as an engine ages; that are corrected in Closed Loop are transferred to the Open Loop operation of the engine.
2.) The difficulty comes when changes are made to the engine that change the relationships between how the engine runs between 5% and 50% Throttle, and how it runs between 50% and 100% Throttle. For example: The computer may be able to maintain 14.7/1 between 5% and 50% Throttle based on O2 Sensor values, and so does not set any Trouble Codes. However, your engine changes may invalidate the relationships that were used in the original computer program to calculate the Fuel Injector pulse widths between 50% and 100% Throttle by looking at the adjustments needed to obtain 14.7/1 between 5% and 50% Throttle. As a result the 50% to 100% Throttle Air Fuel Ratio that were correct with a stock engine may be slightly leaner or slightly richer than what will deliver maximum power.
3.) So when does one need to deal with this at the computer? Well, first of all it's not a zero sum game. The more stuff you change the more of a benefit you may obtain by messin' with the computer. That said, you will be hard pressed to actually damage an engine by not messing with the computer . . . no matter what other changes you make.

 

In addition to that question, it is also what does the software code in the stock ECU ALLOW for? And that is also why tuners are necessary.

What may be fine at a steady 55-60mpg where the bike is most likely tuned for maximum mpg from the factory, may be entirely different at 75-80mph.

Tuning makes a big difference.

 

Thanks blue highways. You have pretty much cleared up any confusion I had on this subject and that explanation should get put as a stickie up top.

 

I noticed that 85mph corresponds to less than 25% of throttle opening because this is our legal cruising speed over here, so well within the 5-50% range. Full acceleration is a different story, and is usually applied during brief duration.

In the ECU, the algorithm or formula to calculate pulse-width (time) needed for injection allows to adjust more rapidly and precisely to the target value with the narrow band sensor. Fewer iterations of calculations are needed by the ECU.
Once the sensor sees its out of the "narrow-band", the ECU tries to correct injection to cancel the error. But this doesn't mean it's perfect for a given style of driving, nor that it is fast enough to compensate the rapid change of regime needed for racing.

 

Did anyone answer the questions of;

The 2012 motors have wide band o2 sensors ??????

If so, whats all that gonna give us ?

Thanks all.
Rowle - UK